Airscrew having adjustable blades



w. c. RUSSELL. AIRSCREW HAVING ADJUSTABLE BLADES.

APPLICATION FILED MAY 15, 1920.

1,389,991 Patente'dSept'. 6, 1921.

2 SHEETS-SHEET 1- W. C. RUSSELL. AIRSCREW HAVING ADJUSTABLE BLADES.APPLICATION FILED MAY 15, 1920.

1,389,991. Patented Sept. 6, 1921.

2 SHEETSSHEET 2.

PATENT OFFICE.

WILLIAM COLIN RUSSELL, OF EAST SHEEN, ENGLAND.

.AIBSCREW HAVING ADJUSTABLE BLADES.

Application filed May 15,

T 0 all whom it may concern:

Be it known that WILLIAM COLIN Ros- SELL, a subject of the King of GreatBritain, residing at 63 Palewell Park, East Sheen, county of Surrey,England, has invented certain new and useful Improvements in andRelating to Airscrews Having Adjustable Blades, of which the followingis a specification, reference being had therein to the accompanyingdrawing.

This inivlention relates to propellers or airscrews for aircraft whereofthe blades are adjustable about their longitudinal axis and has for itsobject to effect certain improve ments which while being particularlyapplicable for use with propellers or airscrews of the kind forming thesubject of my application for Letters Patent Ser. No. 345300 are alsoadapted for employment with airscrews generally where the blades areadjustable in the manner above referred to. a

The present invention consists essentially in the provision of improvedmeans for controlling and operating the adjustment of the blades and forindicating the extent to which the blades are'adjusted at any momentduring flight.

Inconnection with airscrews such as described in my aforesaid priorpatent application and others the mechanism for adjusting the blades isdesigned for actuation by rotary motion and is mounted so as to revolvewith the airscrew it being necessary to impart the said actuating rotarymotion from a non-revolving part of the engine or air craft. I,

Various methods have been proposed or adopted for accomplishing thisoperation,

for instance a gear wheel mounted concentrically with the air screwshaft and meshin with a similar wheel in connection with the bladeadjusting mechanism the said concentric wheel being adapted to normallyrotate with the shaft, but also to be restrained or held stationary bymeans of a band- Specification of Letters Patent.

Patented Sept. 6, 1921.

1920. Serial No. 381,675.

nism. These means of control are normally out of contlnuous positiveconnection with the blade setting mechanism and afiord no gulde to theblade setting at any given moment.

The present invention is designed to pro vide means for effecting thecontrol by a continuous positive connection with the blade adjustingmechanism in conjunction w1th an,indicator adapted to show the exactsetting of the blades at any moment, the means of control being simplein character and convenient either for direct operation by hand orautomatically.

With these ends in view the device of the present invention comprises ablade control gear box mounted conveniently upon a nonrotatingframework, the function of which is to cause a gear wheel or the likemounted concentrically the airscrew shaft and arranged in positiveconnection with the blade seting mechanism to rotate normally' saidconcentric gear wheel by a definite andfr known amount resulting incorresponding proportional adjustment of the airscrew blades andindicator.

In order that the invention may be readily understood and carried intoeffect the same will now be more particularly described with referenceto the accompanying drawings in which Figure 1 is a view in sectionshowing an adjustable airscrew mounting in accordance with my aforesaidprevious application and having the present improvements appliedthereto.

Fig. 2 is a section through the T-shaped headpieceor yoke termination ofthe airscrew shaft showing a means of mounting the chain wheels.

Fig. 3 is a transverse section through the head piece or yoke and pivotsshowing an alternative arrangementof chain wheel drive.

Fig. 4 illustratesanother arrangement in which the concentric gear wheelis carried by a sleeve mounted freely upon the airscrew shaft theoperating shaft being disposed remote from the airscrew shaft.

Fig. 5 is a diagrammatic viewillustrating a form of balanced ordifferential gear for use in effecting the control of the settingmechanism.

Fig. 6 shows a general arrangement of the frame and gear box andgearing. I

Although for convenience of explanation I have shown certain details 'ofthe adjustable airscrew described in my aforesaid former application forLetters Patent Serial No. 3 15300 with my present improvements appliedthereto I do not limit the application thereof to such construction ordetails now, it should be noted in connection with the type ofadjustable airscrew illustrated, that the blade adjusting mechanismbeingirreversible any gearing operating it will be running light except wheneffecting a resetting of the blades. Further it is not sought to claimas an original feature by itself a hollow airscrew shaft as a means ofmounting the operating shaft of-a blade adjusting device or a sleeveupon and concentric with the airscrew shaft as a means of mounting an annular gear wheel.

Referring to Fig. 1 of the drawings the airscrew shaft A terminates in'a tubular T-shaped headpiece or yoke A in which the adjustable bladepivots B and C are mounted the outer pivot B being provided with an endplate B- for the attachment of the butt of the blade (not shown) and theinner pivot C with an end plate 0 for a similar purpose. The rotaryadjusting movement of the pivots is effected 'by means of the drum Dwhereof the helical groove D actuates the levers B and 0* formedorprovided on the respective pivots B and C orthe end plates 1 B Crespectively pertaining thereto. ,The levers B and C respectivelyterminate in pins or studs B and C which engage in the said groove D andthe drum is supported upon an axle D carrying a worm wheel D which maybe rotated by the worm E on the shaft E. It will be seen that upon theworm wheel D being operated by the worm E the rotation of the drum Dwill be effected and the engagement ofthe pinsor studs in the helicalgroove D deflecting the levers B and C" and consequently turning thepivots B and 0 about their axes. The shaft E extends rearward to a pointadjacent to the airscrew shaft terminal. According to the improvedarrangement in which a concentric gear wheel is in positive connectionand. drive with the said shaft E the airscrew shaft Ais formed with ahollow interior for the reception or passage of a shaft H the tubularhead piece A being formed with a recess A to receive the chain wheel Hmounted upon the end of the shaft H. This shaft H is mounted in suitablebearings (not shown) so as to be ca able of rotating freely. The chainwheel nected by a chain H (Fi 2) to a chain wheel E fixed upon the s aftE. As will 1 is conularly Fig. 2, the said chain H passes and worksthrough slots provided by cutting away portions of tubular head piece AOther forms of positive gearing or the like may be em loyed foroperatively connecting the shaft to the shaft E so as to actuate thedrum D or other device for effecting the setting or adjusting of theblades.

According to the alternative arrangement illustrated in Fig. 3 the shaftH is passed directly through the hollow airscrew shaft A head piece Aand pivots B and C the chain wheel H being attached to the protrudingend of the said'shaft H and the connection with the blade settingmechanism being made at the front of the head piece A In order toprovide for the rotation of the pivots B and C about their axes radialopenings or slots 13 and C respectively are formed therein for thepassage of the shaft H.

In another alternative arrangement shown in Fig. 4 a sleeve S is mountedon the airscrew shaft A a concentric gear wheel S being formed with orattached thereto. The sleeve S is freely mounted on the said shaft A andalso carries therewith or has secured thereto a, chain wheel S thelatter being connected by a chain S with a chain wheel H on the drivingshaft H mounted in hearing! on a non-revolving framework. The concentricspur wheel S meshes with a spur wheel E on the shaft E which carries theworm E for-operating the worm wheel 1) pertaining to the drum D of theblade setting or adjusting device. Any form of positive gearing or thelike may be used to transmit' the drive from the shaft H to the shaft Evia the sleeve S, the said shafts A and H being each connectedpositively to the controlling gear box by any convenient form of shaftsor wheels with freedom for the one shaft or wheel to over-run the otherwhile both retain positive driving connection with the main drivingmember.

The component parts of such a gear applied in the present invention willbe more clearly understood by reference to the diagrammatic view Fig. 5wherein an axle N has freely mounted thereon a bevel planet wheel cage Phaving pins P on which bevel planet wheels P are mounted with freedom -Hto rotate and which latter mesh on either side with sun bevel wheels Sand R also freely mounted on the shaft N.- If the cage P be rotated at aconstant speed and one wheel (R for instance) be held stationary theother wheel (S is caused to rotate twice as fast as P and in the samedirection and if the wheel R be also rotated it tends to turn the fellywheel S in the opposite'direction so causing the rotation of the latterwheel to be either accelerated or retarded according to whether therotation of R acts with or against the motion imparted by P. Thus thenormally stationary sun Wheel R can act when rotated as a speedregulator in the transmission of drive from P to S causing the latter togain or lose a definite member of turns in relation to P equal to themember of turns given to R. According to an alternative arrangement ofthe same component parts the wheel B may be the driving member the cageP the regulator normally held stationary and the Wheel S the drivenmember; Rotation'of P then causes the driven wheel S? to gain or lose inrelation to the driving wheel R two turns for every turn of the cage P.

Various re-arrangements of the same component parts may be made to meetthe requirement of a driving member, a driven member and a regulatormember normally held stationary and I do not limit myself to anyparticular arrangement of the said gear nor do I limit myself to anyparticular type of differential or balanced drive gear, such as thebevel type-illustrated, as any of the types designed for use on vehiclesor the like may obviously be adapted to the invention provided the samefunction is performed or fulfilled.

In the application of the differential gearing above described to airscrew blade adjustment the driving member is caused to revolve at aspeed proportionate to and in keeping with that of the airscrew shaftand transmits motion through the .driven member to the concentric gearwheel connected to the blade adjusting mechamsm so that the said gearwheel rotates normally as one with the airscrew shaft but by therotation of the regulator member of the differential gear it may becaused to make'a definite number of turns more or less than the airscrewshaft with a proportionate adjustment of the airscrew blades. Bysuitably connecting the regulator member with. an indicator aregistering or indicating of the exact blade setting at any movement maybe obtained.

Referring now to Fig. 6 which illustrates one form of the gearing andits construction in combination with means of mounting the concentricgear wheel in its appllcatlon to control in connection with thisinvention,the

' justment.

hollow "airscrew shaftA and the central shaft terminate within the gearbox or frame K the said shafts being mounted in suitable bearingsadapted to facilitate their rotation.

The shaft N is also mounted freely in the gear box or frame K and hasfixed thereto the regulator sun wheel R while freely mounted thereon isthe planet wheel ca e or driving member P carrying the pins l for thereception of the freely mounted bevel planet wheels P which mesh on theone side with the fixed wheel R and on the other with the driven wheelS1 also mounQted freely on the shaft N. One end of the shaft N isfurnished with the operating handle M whereby the wheel B may berotated. The cage P carries a gear wheel P which meshes with andrevolves at half the speed of the gear wheel A on the shaft A. Thedriven wheel S carries a gear wheel S which meshes with a ear wheel H ofequal size on theshaft The shaft N at the end remote from the operatinghandle M is fitted with a worm N which is adapted to drive the wormwheel T and the indicator hand or pointer T operatively connectedtherewith the said pointer traversing the scale T so as to show theactual blade setting effected.

. In the operation of the apparatus the handle M is normally locked orstationar Thus the shaft A through spur wheel 5 drives the cage P bymeans of the spur wheel P at half its own speed and in the oppositedirection and by the bevel wheels P rolling around the fixed sun wheelor regulator R also drives the driven wheel S at twice its own speed andin the same direction 2'. e. at the same speed as, but in the oppositedirection to, the shaft A. The wheel S through the spur wheel S drivesthe spur wheel H (of equal size) on the shaft H at its own speed in thesame direction as shaft A. The shafts A and H there fore rotate as oneincluding the concentric gear wheel H '(Fig. 1), which is attached tothe extremit 'of the said shaft H remote from the box I Upon imparting aturning movement to the handle M the fixed regulator wheel R is causedto rotate thereby increasing or decreasing (according to the directionof movement) the extent to which the wheels P must roll in travelingaround it and varying by a similar amount the drive imparted by them tothe wheel S resulting in relative motion between the shafts A and H andthe operation of the blade adjusting mechanism accordingly the pointer Tindicatingor recording the exact amount of ad- The pointer T may havethe speed ratio of its driving gear proportioned to give any convenientindication of airscrew blade adjustment.

A similar arrangement of differential gearing may be combined with themeans of mounting the concentric gear wheel illus trated in Fig. 4 thewhole if'desired being placed immediately behind the airscrew andconstructed in one mechanism.

I do not limit myself to any particular place for mounting the saidcontrolling gear box nor do I limit myself to any specific form ofgearing for conveying motion for driving it or for connecting it to theconcentric gear wheel.

The control shaft N may be adapted for operation by power instead of byhand and automatic control by means of a speed governor may beconveniently applied.

What I claim is 1. In means for propelling aircraft, the combinationwith the propeller shaft of rotative means concentric with said shaft,

mechanism in positive connection with said means for varying the angularadjustment of the propeller blades, and means on the aircraft fortransmitting motion to said concentric rotative means comprising a maindriving member adapted to normally transmit balanced drive to a pair ofdriven members which have the capacity of over-running one another, amember adapted to be held stationary and mounted on the same axis as thedriven members and through the said driven member adapted to drive theconcentric rotative means, and means for rotating said stationary memberto accelerate or retard the movement of said rotative concentrio meansand thereby proportionally op erate the blade setting and adjustingmechanism and effect the setting and adjustment of the propeller'blades.

2. In means for propelling aircraft the combination with the propellershaft of rotative means concentric with said shaft and in positivedriving connection with mecha-- nism for varying the angular adjustmentof the pro-peller blades, and means on the aircraft for transmittingmotion to said eoncentric rotative means, comprising a bal celerate orretard the normal motion of the concentric means to proportionallyoperate the blade setting and adjusting mechanism and effect the settingandadjustment of the propeller blades.

3. In means for propelling aircraft the combination with the propellershaft of rotative means concentric with said shaft and in positivedriving connection with blade setting and adjusting mechanism, means fortransmitting motion to said concentric rotative means, comprising abalanced drive gear embodying a central or epicylic member adapted totransmit balanced drive to a pair of driven members which have thecapacity of over running one another, the drive to the said concentricrotative means being transmitted through the one member of the balancedgear. to the second by holding stationary' the third, means for rotatingsaid sationary member to accelerate or retard the normal motion of theconcentric means, and an indicating device geared to the said normallystationary member and adapted to indicate the amount of motion impartedto the blade adjusting mechanism and the setting of the blades.

4. In means for propelling. aircraft the combination with a hollowpropeller shaft of a concentrically mounted inner shaft adapted tooperate blade setting and adjusting mechanism comprising a helicallygrooved drum and levers in operative relation therewith and adifferential or balanced drive gear adapted to accelerate orretard thesaid inner shaft above or below the normal propeller shaft speed for thepurpose of effecting blade adjustment. 1

5. In means for ropelling. aircraft, the combination with t e propellershaft, of rotative means concentric with said shaft, mechanism inpositive driving connection with said means for varying the angular ad-'justment of the propeller blades, and means on the aircraft fortransmitting motion to said concentric means comprising a pair of drivenmembers which have the capacity of over running oneanother, a maindriving member adapted to normally transmit balanced drive to said pairof driven members, a member adapted to be held stationary and mounted onthe same axis as the driven member and, through the said members, todrive the rotative concentric means, means adapted to rotate saidstationary member to accelerate. or retard the movement of said rotativeconcentric means, and an indicating device operated by the means forrotating the stationary member whereby the proportional operatio of thesetting and adjusting of the propeller blades is effected and indicated.

w. COLIN RUSSELL.

Witnesses: I

F. A. S. SWABKIN, FRANK H. LOVELAND.

